Electrical apparatus



July 1944. R. M. NARDONE ELECTRICAL APPARATUS Original Filed Aug. 27, 1941 2 Sheets-Sheet 1 INVENTOR. Romeo M. Nara/one July 11, 1944. R. M. NARDONE 2,353,317

ELECTRICAL APPARATUS Original Filed Aug. 27, 1941 2 Sheets-Sheet 2 INVENTOR. Romeo M- Nara/one Patented July 11,1944 2,353,317

ELECTRICAL APPARATUS Romeo M. Nardone, Westwood, N. J., assignor to Bendix Aviation Corporation, Bendix, N. 1., a corporation of Delaware Original application August 27, 1941, Serial No.

408,531. Divided and thisapplication November 27, 1942, Serial No. 467,145

2 Claims.

This invention relates to electrical apparatus, and particularly to electrical apparatus of the dynamo class.

An object of the invention is to provide, for application to a dynamoelectric machine, an improved brush lifting mechanism operative to remove the frictional drag of brushes upon a commutating surface whenever it is desirable to do soas, for example, when the commutator is being rotated by some means other than electrical energy transmitted by way of said brushes.

Other objects of the invention will become apparent from inspection of the following specification when read with reference to the accompanying drawings wherein is illustrated the preferred embodiment of the invention. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and

are not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawings:

Fig. 1 is a view of a dynamoelectric machine to which the invention is shown applied;

Fig. 2 is a transverse sectional view along line 2-2 of Fig. 1;

Fig. 3 is an end view of the machine shown in Fi Fig. 4 is a view in elevation of the brush liftingcam; and

Fig. 5 is a view in perspective of manual control means.

In the drawings reference numeral 8 designates an electric motor adapted to be energized by a circuit including a source 25 of stored currrent, a hand-switch 26, and a solenoid 21 (Fig. 5), the latter having a plunger-carried switch element 2! controlling flow of current from source 25 to motor 8.

The brush lifting mechanism is shown in Figs. 1 and 2 as including a ring '56 (see also Fig. 4) having support upon an inner ring 61 of insulating material surrounding bearing assembly 10; said ring 6 6 being shiftable about said supporting ring 61 to a limited extent, as determined by the length of arcuate slot 68 (Fig. 3) at the rear of housing 8, which slot receives a pin ll secured at its inner end to the ring 66 and at its outer end receives a fitting 12 (Fig. 5) serving as an chorage for one end of a link 13 whose outer end is received in a bell-crank l4 operable from the panel I! (at the operator's station) by pushing and pulling of the knob 92 on rod 9!, The interlocking means shown at 86, and the second knob 96, and parts associated therewith, including the u barl51, are claimed in my Patent No. 2,261,402, and need not be further described herein, as they are not essential to the apparatus claimed herein. The outer surface of ring 86 is cut to form a plurality of cam elements corresponding in number and spacing to the number of brushes engagea'ble with the commutator B9 of the motor, and said cam elements are adapted to cooperate with the brush carriages 8i (shown best in Fig. 2) in such manner as to raise the brushes 82 to positions of disengagement with respect to the commutator 69 when the high or outer portions of the cam surfaces are brought into engagement with the projecting arms 84 extending from the brush carriages 8| into the path of rotation of the cam ring 66. The cam ring is normally restrained from movement from the position in which the brushes are engaged. As indicated in Fig. 1, the restraining means takes the form of a spring-pressed detent I 6 registerable with a depression 11 located in the end portion 18 of the housing, and in such position as to assure feeding of current to the commutator by way of the brushes 82 unless and until the cam ring 66 is shifted by actuation of the bell-crank 14. When this occurs, pin Ii rides along slot '68 to the 0pposite end thereof and thereby rotates cam ring '66 in a counter-clockwise direction (as viewed in Fig. 2) to produce a lifting of the brush carriages BI and hence the brushes 82 mounted therein, against the opposition of the opposing springs 19. If desired, an additional detent similar to the detent 16 may be provided to engage with the depression 11 when the pin H has reached the opposite limit of its arcuate stroke, to assure retention of the brushes in the disengaged position.

There is provided as shown in Figure 1 an exteriorly splined sleeve or clutch element 42 which may be adjusted into engaging relation with a corresponding internally splined element formed integral with a fly-wheel, not shown. The flywheel may be of a type such as described and shown in greater detail in my U. S. Patent No. 2,261,402, dated November 4, 1941. As shown therein such fly-wheel may be rotated by manual means as well as by a starter motor.

The clutch element 42 is so arranged that the same may be moved into engaging and disengaging relation with the fly-wheel through operation of the bar 51, controlled by cable 64, as shown in Figure 5. There is further provided novel interlocking means for preventing the shifting of the clutch element 42 to the disengaging position while the brushes are in the engaged position.

The interlocking means, whereby shifting of the bar and clutch element 42 to the disengaged position is rendered impossible while the brushes are in the disengaged position, is shown in Fig. 5 as taking the form of a bar 86 slidable in a guide block Bl to which is anchored a spring 88 normally holding bar 88 in the position shown, in which position its cam-surfaced end registers with the correspondingly shaped cam-surfaced notch 89 in manually operated rod 9| whose outer end projects through panel to receive a knob or handle 92, and whose inner end is received in the brush lifting bell-crank H. The end of bar 36 opposite rod Si is engageable with a notch 93 in rod 94 whose outer end projects through panel 75 to receive a knob or handle 96, and Whose inner end receives the end of the clutch shifting cable 64. Also mounted on rod 94 (but insulated therefrom) is a switch bar 91 normally bridging contacts 98 in the circuit to relay 21.

With the arrangement illustrated, outward movement of rod 9i will slide bar 86 into locking engagement with rod 94, thus making it impossible to disengage clutch 42 so long as the said rod 9i remains in the outer (brush lifted) position. Thus, there is automatic assurance that, during manual acceleration of flywheel, with the brushes raised to eliminate friction drag, the inertia of the motor armature will be available to supplement that of the flywheel. If, on the other hand, the operator finds that, under existing conditions in a given instance, he does not require this added inertia effect, he may relieve himself of the burden of manual acceleration of the additional weight constituted by the motor armature. This he will do by pulling outwardly on member 94, to disengage clutch 42. This action, incidentally, will lock the brushes against being raised; but this is immaterial, since there can be no energization of the motor 8, as the outward pull of rod 9| causes the motor energizing relay circuit to be held open at the switch 91. Thus accidental energization of the motor, during use of the manual means for flywheel acceleration, is precluded.

This application is a division of my application Serial No. 408,531, filed August 27, 1941.

What is claimed is:

1. The combination, with a motor armature and commutator, of a supporting housing including a bearing assembly at the commutator end of the motor, a set of brushes engaging said commutator, and means including a ring surrounding said bearing assembly for disengaging said brushes from said commutator, said brush disengaging means further including wire receiving terminals for the respective brushes, each wire receiving terminal having an arm projecting laterally therefrom, a plurality of cam surfaces on said ring, each cam surface being engageable with one of said wire receiving terminals to raise the brush carried therein, and an annular ring of insulating material to hold said first-named ring in spaced relation to said bearing assembly.

2. The combination, with a motor armature and commutator, of a supporting housing including a bearing assembly at the commutator end of the motor, a set of brushes engaging said commutator, means including a ring surrounding said bearing assembly for disengaging said brushes from said commutator, and means including an annular ring of insulating material to hold said first-named ring in spaced relation to said bearing assembly.

ROMEO M. N ARDONE. 

